Olivia Newton-John played Sandy in 'Grease' and released hit songs like 'Physical' and 'Have You Never Been Mellow,' but what's the icon up to these days?

Then:

Australian sensation Olivia Newton-John hit the pop charts full-force in the '70s, and represented the UK in the 1974 Eurovision Song Contest with 'Long Live Love,' placing fourth in the contest (the winners that year were Swedish pop group ABBA).

Her records landed gold on the Billboard charts, but in 1978 her career really took off when she starred as Sandy opposite John Travolta's Danny in the film adaptation of the Broadway show 'Grease' -- wherein she went from goody-goody to naughty-naughty in order to win over the school's bad boy.

After that, her career in the '80s was unstoppable -- she worked with legends like Andy Gibb of the Bee Gees and Elton John, and starred in the wacky musical movie 'Xanadu.'

Now:

Tim Whitby, Getty Images

Olivia Newton-John continued to record music throughout the '90s and the '00s, releasing a holiday duet album called 'This Christmas' with her 'Grease' co-star John Travolta last year. She's had the occasional guest role on shows like 'Kathy Griffin: My Life on the D-List' and a two-episode arc on 'Glee.'

A breast cancer survivor and longtime activist, Newton-John has worked for cancer charities and UNICEF, and sadly just lost her sister Rona to a brain tumor.